Posted: Thu Aug 21, 2008 21:17 Post subject: Recommendations for point-to-point-to-point
I am trying to put together a soltion to solve the following problem: I need to get an Internet connection from one location to another, which is about 2 miles away, and around a corner. My thought it to use ALIX-based hardware running DD-WRT. I have used DD-WRT on many devices and love it!
At point A, I will put an ALIX board with a single LAN port and a single mini-PCI wireless card attached to a directional antenna, pointing toward point B. The LAN port will be connected to the Internet connection.
At point B, I will put an ALIX board with a single LAN port and two mini-PCI wireless cards attached to two directional antennas, one pointing toward point A and the other pointing toward point C. The LAN port will be strictly for PoE. DD-WRT would be configured to bridge between the two wireless cards.
At point C, I will put an ALIX board with a single LAN port and a single mini-PCI wireless card attached to a directional antenna, pointing toward point B. The LAN port will be connected to an Ethernet switch, allowing the devices at this location to utilize the Internet connection from point A.
The distance from point A to point B is about 1.75 miles. There are two trees and a small building somewhat obstructing line-of-sight. The distance from point B to point C is about .25 miles, and is obstructed with a lot of trees (a forest). I have already sucesfully penetrated this forest with two 400mW Engenius wireless bridges, so I'm hoping I will have no problems with another solution.
Can anyone provide me with their thoughts on how feasible this sounds, and offer any advice for a successful implementation? Hardware advice such as wireless card, anntenna, or enclosure recommedations are especially appreciated, as would be ideas on antenna alignment, DD-WRT configuration, or anything else for that matter! Thanks very much to anyone that can help out.
I could really use a recommendation for high-powered, reasonably priced mini PCI cards to use with the ALIX board, that will be recognized by DD-WRT. I'm considering the Engenius EMP-8602 Plus-S or the Ubiquiti XR2. The XR2 costs about twice as much as the EMP-8602. Both are 600mW cards.
I'm also wondering which wireless type, 802.11a, 802.11b, or 802.11g, would give me a better signal through the trees.
I could really use a recommendation for high-powered, reasonably priced mini PCI cards to use with the ALIX board, that will be recognized by DD-WRT. I'm considering the Engenius EMP-8602 Plus-S or the Ubiquiti XR2. The XR2 costs about twice as much as the EMP-8602. Both are 600mW cards.
teh emp cards are ok. i have 2 of the stanrdard power 8601 and they are performing good
Quote:
I'm also wondering which wireless type, 802.11a, 802.11b, or 802.11g, would give me a better signal through the trees.
Posted: Wed Sep 10, 2008 0:22 Post subject: Repeater Bridge not an option?
So I finally got all my test hardware together, and my x86 key for DD-WRT v24SP1, and am trying to follow the instructions from http://www.dd-wrt.com/wiki/index.php/Repeater_Bridge in order to build the first segment of my bridge. Step 3 says to set Wireless Mode to Repeater Bridge. However, in the Basic Settings tab of the main Wireless tab, the only options I have under Wireless Mode are AP, Client, Client Bridge, Adhoc, WDS Station, and WDS AP. No Repeater Bridge option. Am I missing something? I got the impression from reading other posts that Client Bridge is not desirable in my situation because it does not create a transparent bridge, which is what I would want here, so that devices on either side of the bridge would be totally unaffected by the bridge, as if the wireless bridge were simply a really long ethernet cable.
OK, I have configured WDS as instructed. My bridge is working, but not as well as I had hoped. One thing that has me concerned is that the mini PCI cards I have attached to the ALIX board, Engenius NMP8602+S, are supposed to be 600mW/28dbm cards, but no matter what I set the TX Power to, on the Wireless Status page they are both listed to have an Xmit of 25 dbm. I can set them lower, and that gets reflected on the status page, but I cannot set them higher. I even tried disabling one card in case it was a power issue, but that did not help. Any suggestions? Thanks in advance!
Sash, I'd like to say thanks for the quick responses and continued support.
I did check the specs on these cards before posting, here's what I found:
2.412~2.472G(IEEE802.11b)
28dBm. @ 1, 2, 5.5 and 11Mbps
I should have mentioned in my previous post that I have the following settings:
Wireless Network Mode: B-only
Wireless Channel: 1 (2412 MHz)
Transmission Max Rate: 1 Mbps
Transmission Min Rate: 1 Mbps
Sensitivity Range (ACK Timing): 800
TX Power: 28 dBm
Signal strength hovers around 30%.
I forced B-only and 1 Mbps min/max in hopes that I would then see the TX Power on the Wireless Status screen go up to the 28 dBm that I have it configured for. However, I cannot get it to go above 25 dBm, even though the card should be capable of 28 dBm at this frequency and band.
It's also strange that no matter what I set the Transmission Rates to, Rate always says Auto on the Wireless Status screen.
Finally, the distance I'm trying to cross here is about 350 meters, so I set the ACK Timing to 800 (double the distance plus about 10%, then rounded up). However, on the Wireless Status screen, it shows 30us (3900m). I have tried various other values and have not been able to get the value below 28us (3600m).
Any idea why these few settings do not seem to take effect?
Just some quick background: These are the settings for the device at point B on the map. It is an ALIX3C2 board with two Engenius NMP8602+S mini PCI cards. Each card is attached to a HyperlinkTech 14dBi directional panel antenna, part numbers HG2414P. These have an integrated 1 foot cable. The antenna connected to ath0 points toward A, and the antenna connected to ath1 points toward C. The device is running dd-wrt v24-sp1.
This first attachment shows the settings for ath0.
And here is what the status screen shows for ath0. Note that the TX Power, Rate, and ACK Timing do not seem to match what I entered in the settings screen.
